Mobile communication systems have been developed to provide voice services while ensuring activities of users. However, mobile communication systems have evolved to support data services beyond the voice services. Nowadays since a shortage of resources is caused due to explosive increase of traffic and users require services at a much higher speed, more advanced mobile communication systems are demanded.
The next-generation mobile communication systems are largely required to support accommodation of explosive data traffic, considerable increase of data rate per user, accommodation of a significantly increased number of connected devices, very low end-to-end latency, and high energy efficiency. To this purpose, research on various technologies is being conducted, such as dual connectivity, massive MIMO, in-band full duplex, NOMA (Non-Orthogonal Multiple Access), super wideband, and device networking.